1. Field of Invention
This invention generally relates to portable tree hoist, specifically hoist capable of raising and lowering game feeders or for dressing game animals.
2. Prior Art
When hunting large game such as deer, It is often times desirable and necessary to dress a fallen animal in the field. There are many advantages to field dressing. For example, by leaving behind the unwanted portions of the animal in the field you considerably reduce the overall weight for transportation of the desirable remains. Furthermore, prompt gutting decreases the temperature around the desirable meat reducing the chance of meat spoilage.
While field dressing of game animals is desirable, it also requires that you have means to elevate the fallen animal so that the exposed meat does not get soiled and contaminated. Often times the fallen animal is deep into wooded areas inaccessible by vehicle means. Therefore, there is a need for a portable, compact, lightweight hoisting device which can easily be attached to a tree and operated by a single individual.
Similarly, game feeders such as ones used to disperse corn to deer are often set up in remote wooded areas. These feeders are most commonly made with a drum which houses corn and includes a motor to dispense the corn at determined time intervals. Therefore, a portable, compact, lightweight hoisting device is desirable for lifting and lowering game feeders in remote settings.
Many hunters use a well known Block and Tackle Pulley Technology which utilizes a series of pulleys to reduce the amount of pull required to lift a desired weight. These systems include a hook at the upper end which are often attached to a tree limb for upper support. Another hook at the lower end can be connected to a gambrel for attachment to a deer carcass or for direct attachment to a game feeder (For more on “Block and Tackle Pulley Systems” see www.howstuffworks.com/pulley.htm). The problem exist with finding a tree limb strong enough to support the required weight and with the safety issues required to attach to such.
One prior art product utilizes a patented locking single pulley (U.S. Pat. No. 5,368,281 and U.S. Pat. No. 5,722,640) at the lower end and a separate free turning pulley at the upper end to create a Block and Tackle arrangement (The patented Rope Ratchet and the Hang-'em High Hoist can be viewed at www.roperatchet.com/index.shtml). The amount of force required to lift the desired weight is cut in half. While beneficial, a 2:1 pulling ratio is not sufficient for lifting large deer or even 35 gallon drum feeders filled with corn. In either case, the weight to be hoisted exceeds 200 pounds. Experimenting, I have found that a 4:1 ratio is needed to pull 200 pounds with any ease. My invention is designed with a 6:1 pulling ratio for these same concerns. Additionally, pulleys can not be added to the Hang-'em High Hoist as designed to increase the lifting ratio. The lower pulley which is the patented Ratchet Rope Pulley on the Hang-'em High Hoist does not have means to attach additional pulleys.
U.S. Pat. No. 5,263,675 to Roberts and Gribling, Jr. (1993) is a portable support assembly consisting of a vertical support, a horizontal support and a diagonal support. The disadvantages of this device is that the supported item has to be lifted onto the support assembly. Lifting fallen game such as white tail deer in this manner is cumbersome and generally requires more than a single individual. Secondly, a considerable amount of assembly is required.
U.S. Pat. No. 5,562,534 to McGough (1996) is a portable game hoist which comprises a vertical backing member, a horizontal support frame and a diagonal brace with a winch support at the lower end. McGough's device is mostly welded and therefore is not collapsible to allow easy transport. Furthermore, McGough's device, as with most other comparable hoisting devices, utilizes a winch and cable for lifting. In all but one of the patents I researched, no specification was made for use of an automatic brake winch. It is a serious safety issue to hoist heavy items with a marine trailer type winch. For the lifting process, a marine trailer winch automatically holds the weight as the item is being raised but this is not true for the lowering process. For the decent, once the stop lever is released from the drum gear, the weight of the item hoisted must be manually held back. If you release the stop lever and let go of the handle, the hoisted item will fall suddenly and the winch handle will spin violently. The use of an automatic brake winch is designed to automatically hold the lifted weight during the assent and the decent. The problem with an automatic brake winch, as with a marine trailer winch, is that the added weight of a winch becomes a concern when a hand held portable hoist is desired. Furthermore, an automatic winch is more expensive than a marine trailer winch; and therefore, it becomes an overall cost concern. In addition, if a winch is connected to a compact hoisting frame and is attached to a tree out of reach, the winch operator must climb the tree in order to actuate the winch. If the hoisting device is designed so that the winch can be actuated at ground level with the support frame above, the portability of the unit is compromised.
U.S. Pat. No. 5,820,455 to Breedlove (1998) is a portable game hoist comprising a vertical member, a horizontal member, and a diagonal member. One disadvantage of this device is that the bottom portion of the hoist is not strapped to the tree. Instead, a sharp bracket attached to the bottom of the hoist engages the tree. If the hoist is bumped or bounces for any reason, the hoist could slide by the supporting post causing hoist failure. Also, some assembly is required at the point of use which may require the need for tools. Furthermore, the rope and pulley system described does not have a locking feature to prevent sudden hoist failure if hands slip from the rope. Also, hoisted items must be tied off to a near by tree or the like in order to hold the lifted weight.
U.S. Pat. No. 6,045,442 to Bounds (2000) is a game hoist comprising two vertical supports, two horizontal supports, and a diagonal support. One disadvantage of Bound's device is that it does not collapse into a compact unit for easy transport. A compact unit is oftentimes needed for field dressing of fallen game in dense locations. Secondly, because the winch is separated from the main frame, more set up time is required. When a hoisting device is primarily used for field dressing of fallen game, it is continuously being set up and taken down. Therefore, it is desirable to have a hoisting apparatus which minimizes the amount of set up and take down time required. Finally, the height of the gambrel in the maximum hoisted position is considerably lower than the uppermost horizontal member.
U.S. Pat. No. 6,062,974 to Williams (2000) is a portable game support consisting of a upper arm and a lower arm. While in use, the upper arm is horizontal and is attached to a vertical columnar structure via a chain. The lower arm is diagonal and has two spikes to engage the tree or pole. The problem with William's game support is that the lower arm is not chained or strapped to the vertical columnar member; therefore, if the device is bumped or bounces for any reason, the lower arm could slide down the vertical columnar member causing the hoisted item to drop violently. Furthermore, the single pulley design shown is not sufficient.
U.S. Pat. No. 6,739,964 to Gearhart (2004) is a V-shaped hoist which has an upper frame designed similar to that of climbing tree stands. A rear retaining bar supports the weight on the rear side of the tree or pole, while a V-shaped blade bites into the hoisting side of the tree/pole. A winch is attached separately to the tree/pole via a winch bracket below the upper frame. The disadvantage of Gearhart's device is that it is not collapsible. While the unit can be partially disassemble into a single package for portability, it is bulky and would be cumbersome to carry by hand as are most tree climbing devices.
U.S. Pat. No. 6,695,688 (2004) by James an Alva Owens is a portable hoist designed to be attached to a tree or pole comprising a vertical member and a pivoting support arm. The pivoting support arm is near horizontal while in use. One disadvantage of this device is that the winch must be operated while attached up on the tree and may require elevation means to the operator of the winch. Also, a winch can easily fail if the winch gear locking lever is accidentally disengaged while under load. If this occurs, the load will drop immediately, possibly causing injury to person(s) tending to the lifted object. Another disadvantage of Owens' device is the lack of a diagonal support member which distributes part of the load back to the vertical columnar structure. Without a diagonal support or other means to distribute load, the removable bolt or ball pin is the main means for support. Over time the pin could shear, causing hoist failure.
U.S. Pat. No. 5,975,831 to Martin (1999) and U.S. Pat. No. 6,138,991 to Myers are examples of hoisting devices which require attachment to a vehicle such as an all terrain vehicle (ATV). This type of device can only be used where ATV use is allowed. ATV use is generally prohibited on state-owned game lands. Also, the use of ATV game hoists are obviously restricted to owners of ATV's.
Other patents and patent applications which may have some pertinence to the present invention may include;
U.S. Pat. No. 6,152,675 to Compton (2000)
U.S. Pat. No. 6,705,821 to Phillips (2004)
U.S. Pat. No. 6,250,483 to Frommer (2001)
Patent Application No. 20040026675 to Green (2004)
Patent Application No. 20050136816 to Lake (2005)
Patent Application 20030000906 to Perkins (2003)